Characterization of stainless steel corrosion processes in mortar using various monitoring techniques

Monitoring of the corrosion on stainless steel type AISI 304 in highly porous mortar specimens was performed during a period of 2 years. The carbonated mortar specimens were cyclically wetted by a 3.5% NaCl solution, with drying periods in between. Five different monitoring techniques were applied: the galvanostatic pulse, the coupling current, the use of coupled multi-electrode arrays and electrical resistance probes and electrochemical impedance spectroscopy. At the end of the exposure period, comparisons were made between the results obtained by using these different techniques, as well as by taking into account actually observed damage by spectroscopic techniques. The advantages and limitations of each of the applied monitoring techniques were assessed. (C) 2019 Published by Elsevier Ltd.